ADU rules in Laredo

Laredo has no ADU ordinance; the phrase accessory dwelling unit appears nowhere in either code. In the R-1 and R-1B single-family districts only one dwelling per lot is allowed, so a detached second unit with its own kitchen is prohibited there. A detached second dwelling on one lot is expressly allowed only in the R-3 Mixed Residential District, and only if it is occupied by a relative, produces no rental income, the lot provides 3,000 sq ft of area per dwelling unit, and 1.5 parking spaces per unit are on the lot. The RS district additionally permits guest quarters separated from the principal structure as an accessory use, but a guest quarters is not a dwelling unit.

An attached second unit with its own kitchen makes the building a two-family dwelling (duplex), which the land use chart permits by right in AG, R-2, R-3, R-O, AE, B-1, B-1R, CBD, and B-3, but not in the R-1, R-1A, R-1B, R-1-MH, RS, or RSM districts. Separately, the chart lists Servants Quarters as a permitted use in R-1, R-2, R-3, RSM, RS, R-O, and most business districts; the code never defines that term, and the RS district text limits servants quarters to space for domestic employees within the main structure. An attached family or staff suite is broadly achievable, but a true second dwelling attached to a house in an R-1 district is not authorized.

Laredo controls second units through lot area and district dimensional standards rather than a square-footage cap on the unit itself; no maximum unit size for a second dwelling, servants quarters, or accessory building was found anywhere in the LDC. Accessory buildings must sit at least 2.5 ft from side and rear lot lines.

No section requires the owner to live on the property, but the only path to a second unit on a single-family lot (R-3) requires the additional dwelling to be occupied by a relative and bars using it for rental income, which ties the unit to the resident household in practice. Duplexes in the districts that allow them carry no occupancy restriction at all. Read the R-3 relative condition as stricter than a typical owner-occupancy rule, since the unit cannot be rented to anyone.

Parking for detached dwellings must be on the same lot as the dwelling. Adding a second unit in R-3 means 1.5 spaces per unit, so a lot with two units needs 3 spaces. A duplex conversion triggers the 4-space duplex formula, and any change of use or added units requires the additional parking at permit time.

Every second-unit path Laredo offers (servants quarters, duplex in eligible districts, the R-3 second dwelling) is marked 'X', a by-right permitted use, on the land use chart; none requires a special or conditional use permit. A building permit from the Building Official is mandatory before any structure is erected, changed, converted, or enlarged, with a site plan. Outside the eligible districts the use is simply prohibited, so the real gate is the zoning district, not a discretionary hearing.

The no-rental-income condition is the defining limit on Laredo's only single-lot second-dwelling allowance, so an income ADU in the modern sense is not authorized in residential districts. Long-term rental of a lawful duplex unit is unrestricted by the code. Short-stay operators owe city hotel occupancy tax even though no STR licensing scheme exists (verified by zero-hit full-text searches of both codes, July 2026).